Heightening mechanical properties and thermal shock resistance of low-carbon magnesia-graphite refractories through the catalytic formation of nanocarbons and ceramic bonding phases

摘要

The in situ catalytic formation of nanocarbons and ceramic bonding phases in low-carbon magnesia -graphite refractories is one of the significant strategies for heightening their mechanical properties and thermal shock resistance. Here, effect of aluminum content and nickel-containing catalyst addition on microstructural evolution, mechanical and thermo-mechanical behavior of such refractories was explored. Under the function of the catalyst, addition of aluminum powders allowed the newly growth of plenty of nanocarbons (e.g., carbon nanotubes and carbon onions), and also accelerated the in - situ formation of more ceramic bonding phases (e.g., magnesia whiskers and spinel whiskers/particles, etc.) in samples. This occurrence optimized significantly the microstructure of samples, correspondingly giving rise to their superior mechanical properties and thermal shock resistance. This work might provide a path for exploring low-carbon magnesia-graphite refractories with high performances. (C) 2018 Elsevier B.V. All rights reserved.